Many people suffer from seasonal allergies and face an increased number of colds, coughs, and the flu more so in the winter than in the summer. Researchers from the Juvenile Diabetes Research Foundation/Wellcome Trust Diabetes and Inflammation Laboratory in the U.K. now have evidence that explains why specific conditions appear to be worse in the winter and why people tend to be healthier during the summer months. The study looked at heart diseases, type 1 diabetes, and rheumatoid arthritis.
This study, GEN News reports, is one the first of its kind to provide evidence that differences in disease behavior may actually be the result of immune system variances due to changes in the season.
In some ways, its obvious it helps explain why so many diseases, from heart disease to mental illness, are much worse in the winter months - but no one had appreciated the extent to which this actually occurred. The implications for how we treat disease like type 1 diabetes, and even how we plan our research studies, could be profound, said John Todd, Ph.D., director of the JDRF/Wellcome Trust Diabetes and Inflammation Laboratory and senior author on the study.
Scientists examined more than 16,000 samples of blood and adipose tissue from individuals in both northern and southern hemispheres, including people from the U.K., the U.S., Iceland, Australia, and The Gambia.
After examining cell types in the blood and looking at the expression levels for different genes, scientists found that thousands of genes were expressed depending on what time of the year the samples were taken. These results were observed across mixed populations and ethnically diverse backgrounds.
Additionally, the researchers found that the gene ARNTL, which codes for a transcription factor that suppresses inflammation in mice, was more active in the summer and less so in the winter.
